package com.tomatozq163.structure;

public class ArrayQueue<E> implements Queue<E> {
    private Array<E> array;

    public ArrayQueue(int capacity){
        array = new Array<>(capacity);
    }

    public ArrayQueue(){
        array = new Array<>();
    }

    @Override
    public void enqueue(E o) {
        array.addLast(o);
    }

    /**
     * 时间复杂度：O(n)
     * @return
     */
    @Override
    public E dequeue() {
        return array.removeFirst();
    }

    @Override
    public E getFront() {
        return array.get(0);
    }

    @Override
    public int getSize() {
        return array.getSize();
    }

    @Override
    public boolean isEmpty() {
        return array.isEmpty();
    }

    public int getCapacity(){
        return array.getCapacity();
    }

    @Override
    public String toString() {
        StringBuilder res = new StringBuilder();

        res.append("Queue:");
        res.append("front [");

        for (int i = 0; i < array.getSize(); i++) {
            res.append(array.get(i));

            if (i!=array.getSize() - 1)
                res.append(",");
        }

        res.append("] tail");

        return res.toString();
    }

    public static void main(String[] args){
        ArrayQueue<Integer> queue =new ArrayQueue<>();

        for (int i = 0; i < 10; i++) {
            queue.enqueue(i);
            System.out.println(queue);

            //每入队三个，离队一个
            if ((i+1) % 3 == 0){
                queue.dequeue();
                System.out.println(queue);
            }
        }
    }

}
